What is the difference between D and EE widths?

EE widths will be roughly ⅔ of a size larger than D widths in terms of width and volume. If you don’t normally wear wide widths in your other footwear, you likely won’t need EE widths in boots.

If you do typically wear EE widths, but you are interested in a model which is only carried in D widths, start by going up a half size. For example, an 11.5D will be similar in width and volume to an 11EE once fully broken in.